import {CHANGE_INPUT_VALUE,ADD_TODO_VALUE,DELETE_TODO_VALUE} from './actionTypes'
const defaultState = {
  inputValue: "",
  list: []
}

//reducer 可以接受state，但不能修改state
export default (state = defaultState,action) => {
  if(action.type == CHANGE_INPUT_VALUE){
    const newState = JSON.parse(JSON.stringify(state))
    newState.inputValue = action.value
    return newState
  }

  if(action.type == ADD_TODO_VALUE){
    const newState = JSON.parse(JSON.stringify(state))
    newState.list.push(newState.inputValue)
    newState.inputValue = ""
    return newState
  }

  if(action.type == DELETE_TODO_VALUE){
    const newState = JSON.parse(JSON.stringify(state))
    newState.list.splice(action.index,1)
    return newState
  }
  return state
}